1. Field of the Invention
This invention relates to a fluorescent display panel. More particularly this invention relates to a fluorescent display panel having a CIG (chip in glass) structure containing a driver integrated circuit chip.
2. Description of the Prior Art
This type of fluorescent display panel generally has a vacuum chamber enclosed by an insulating substrate and a glass cover fixed thereon. The vacuum chamber contains an anode fixed on the substrate and having a fluorescent material applied thereon to form a display pattern. Spaced filaments are disposed opposed to the anode. A grid is placed between the anode and the filaments. An integrated circuit chip (IC chip) drives to drive the anode or the grid. The IC chip is fixed on the substrate and covered with a box type metallic shield to protect it from an electromagnetic field. On both sides of the shield, external leads, which are projected from the vacuum chamber, are connected.
A proposed method of fabricating such a conventional fluorescent display panel is to prepare a flat metallic frame of monolithic formation of grid supports, filament supports, an IC chip shield and external leads, and to press-mold the frame. The shield is formed into a box shape by this process. This proposed method, however, has a disadvantage of dispersion of position and/or height of the formed shield because the shield is press-molded while it projects the connected external leads on both sides, which may result in the production of a substandard shaped shield. Dispersion of shield height is critical, because it will degrade the shielding effect.
Further, this method has a problem of misalignment of position and/or height of the grid supports and/or the filament supports because the frame itself is subjected to a slight deformation during the molding process.
Accordingly, an object of this invention is to provide a fluorescent display panel which allows the position and height of an IC chip protection shield to be set with a high accuracy.
Another object of this invention is to provide a fluorescent display panel which allows accurate setting of the position and height of elements other than the IC chip protection shield including grid supports and filament supports.